There is known a technique for attaching a fusible plug valve to a high pressure gas container to reduce a pressure in the container when the container is exposed to a high temperature environment. The fusible plug valve is a valve composed of a housing integrated with a boss portion of the container serving as an in-out flow port of high pressure gas and including a flow passage penetrating from the inside to the outside of the container, and a substantially cylindrical fusible plug for closing the flow passage. The fusible plug is made of a metal having a low melting point and melts by being exposed to a high temperature. This causes the high pressure gas in the high pressure gas container to be released to outside through the flow passage even if the container is exposed to a high temperature environment, whereby it can be suppressed that the pressure in the container becomes a high pressure beyond a normal use range.
Metallic materials and carbon fiber reinforced plastics are used as a material of a body of the high pressure gas container. Nowadays, carbon fiber reinforced plastic materials are widely used as reinforcing materials in terms of strength and weight saving. On the other hand, in the case of using a material having a low thermal conductivity such as carbon fiber reinforced plastic as the material of the high pressure gas container body, heat hardly transfers in the container body. Thus, if a part of the container is heated at a position distant from the fusible plug valve such as a container end part on an opposite side, it may possibly take time until this heat is transferred to the fusible plug valve. In such a case, the melting of the fusible plug valve as described above does not occur despite a temperature increase in a part of the container, an internal pressure may increase and the durability of the container may be reduced.
Against this problem, a high pressure gas container in which a heat conductor extends from a fusible plug valve provided in the high pressure gas container along a side surface of a container body outside the container to transfer heat to a safety valve is disclosed in JP2005-315294A.